Patent Literature 1 discloses a device enabling fuel feeding, that is attached to an upper end of a filler pipe (also referred to as an inlet pipe), and is opened by insertion of a fuel filler nozzle of a fuel filler gun.
The device of Patent Literature 1 has an upper side closing body and a lower side closing body that are pushed and opened by the fuel filler nozzle, and thereby, the device does not need a screwed-type fuel filler port cap.